<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <title>Document</title>
    <style>
        
    </style>
</head>
<body>
    
</body>
<script>
    // 任何两个对象都不相等
    // var arr1 = [];
    // var arr2 = new Array();
    // var arr3 = [];
    
    // console.log(arr1);
    // console.log(arr2);
    // console.log(arr3);

    // console.log(arr1 === arr2);
    // console.log(arr1 === arr3);

    // var str1 = "hello";
    // var str2 = "hello";
    // console.log(str1 === str2);


    // var arr1 = ["hello", "world"];
    // var arr2 = new Array("hello", "world");
    // var arr1 = [2,3,4];
    // var arr2 = new Array(2,3,4);
    var arr1 = [5];
    var arr2 = new Array(5);
    console.log(arr1);
    console.log(arr1.length);
    console.log(arr2);
    console.log(arr2.length);
    // 有且只有一个数值型数据时，字面量就是作为数据存储，构造函数作为长度使用，每个数据都是undefined
</script>
</html>